textual.filter

Filter classes.

Note

Filters are used internally, and not recommended for use by Textual app developers.

Filters are used internally to process terminal output after it has been rendered. Currently this is used internally to convert the application to monochrome, when the NO_COLOR env var is set.

In the future, this system will be used to implement accessibility features.

NO_DIM module-attribute

NO_DIM = Style(dim=False)

A Style to set dim to False.

ANSIToTruecolor

ANSIToTruecolor(terminal_theme)

Bases: LineFilter

Convert ANSI colors to their truecolor equivalents.

Parameters:

Name	Type	Description	Default
terminal_theme	TerminalTheme	A rich terminal theme.	required

apply

apply(segments, background)

Transform a list of segments.

Parameters:

Name	Type	Description	Default
segments	list[Segment]	A list of segments.	required
background	Color	The background color.	required

Returns:

Type	Description
list[Segment]	A new list of segments.

truecolor_style cached

truecolor_style(style)

Replace system colors with truecolor equivalent.

Parameters:

Name	Type	Description	Default
style	Style	Style to apply truecolor filter to.	required

Returns:

Type	Description
Style	New style.

DimFilter

DimFilter(dim_factor=0.5)

Bases: LineFilter

Replace dim attributes with modified colors.

Parameters:

Name	Type	Description	Default
dim_factor	float	The factor to dim by; 0 is 100% background (i.e. invisible), 1.0 is no change.	0.5

apply

apply(segments, background)

Transform a list of segments.

Parameters:

Name	Type	Description	Default
segments	list[Segment]	A list of segments.	required
background	Color	The background color.	required

Returns:

Type	Description
list[Segment]	A new list of segments.

LineFilter

Bases: ABC

Base class for a line filter.

apply abstractmethod

apply(segments, background)

Transform a list of segments.

Parameters:

Name	Type	Description	Default
segments	list[Segment]	A list of segments.	required
background	Color	The background color.	required

Returns:

Type	Description
list[Segment]	A new list of segments.

Monochrome

Bases: LineFilter

Convert all colors to monochrome.

apply

apply(segments, background)

Transform a list of segments.

Parameters:

Name	Type	Description	Default
segments	list[Segment]	A list of segments.	required
background	Color	The background color.	required

Returns:

Type	Description
list[Segment]	A new list of segments.

dim_color cached

dim_color(background, color, factor)

Dim a color by blending towards the background

Parameters:

Name	Type	Description	Default
background	Color	background color.	required
color	Color	Foreground color.	required
factor	float	Blend factor	required

Returns:

Type	Description
Color	New dimmer color.

dim_style cached

dim_style(style, background, factor)

Replace dim attribute with a dim color.

Parameters:

Name	Type	Description	Default
style	Style	Style to dim.	required
factor	float	Blend factor.	required

Returns:

Type	Description
Style	New dimmed style.

monochrome_style cached

monochrome_style(style)

Convert colors in a style to monochrome.

Parameters:

Name	Type	Description	Default
style	Style	A Rich Style.	required

Returns:

Type	Description
Style	A new Rich style.